Strokes are the third leading cause of death in the United States, causing approximately 177,000 deaths per year, and strokes are the number one cause of long-term disability in the United States, currently affecting nearly 5 million people. Strokes are caused by an abrupt interruption of the blood supply to the brain or spinal cord, thereby depriving the tissue of oxygen and resulting in tissue damage.
Strokes typically occur in one of two forms: (i) hemorrhagic stokes, which occur with the rupture of a blood vessel; and (ii) ischemic strokes, which occur with the obstruction of a blood vessel.
Rapid diagnosis is a key component of stroke treatment. This is because the treatment for an ischemic stroke may be contra-indicated for the treatment for a hemorrhagic stroke and, furthermore, the effectiveness of a particular treatment may be time-sensitive. More particularly, the current preferred treatment for an acute ischemic stroke, i.e., the administration of tPA to eliminate clots, is contra-indicated for a hemorrhagic stroke.
Furthermore, the clinical data suggests that the medication used to treat ischemic strokes (i.e., tPA) is most effective if it is administered within 3 hours of the onset of the stroke. However, current diagnosis times, i.e., the time needed to identify that the patient is suffering from a stroke and to identify the hemorrhagic or ischemic nature of the stroke, frequently exceeds this 3 hour window. As a result, only a fraction of current ischemic stroke victims are timely treated with tPA.
Imaging is generally necessary to properly diagnose (and hence properly treat) a stroke. More particularly, imaging is generally necessary to: (i) distinguish strokes from other medical conditions; (ii) distinguish between the different types of strokes (i.e., hemorrhagic or ischemic); and (iii) determine appropriate treatments (e.g., the administration of tPA in the case of an ischemic stroke).
Computerized Tomography (CT) has emerged as the key imaging modality in the diagnosis of strokes. CT scanners generally operate by directing X-rays into the body from a variety of positions, detecting the X-rays passing through the body, and then processing the detected X-rays so as to build a computer model of the patient's anatomy. This computer model can then be visualized so as to provide images of the patient's anatomy. It has been found that such CT scanning (including non-enhanced CT scanning, CT angiography scanning and CT perfusion scanning) is able to provide substantially all of the information needed to effectively diagnose (and hence properly treat) a stroke.
Unfortunately, in practice, the CT machine is typically located in the hospital's radiology department and the patient is typically received in the hospital's emergency room, and the “round-trip” time between the emergency room and the radiology department can frequently involve substantial delays, even in the best of hospitals. As a result, the time spent in transporting the patient from the emergency room to the radiology department and then back again can consume critical time which can compromise proper treatment of the patient.
For this reason, as well as others, NeuroLogica Corporation of Danvers, Mass. has recently developed a mobile CT imaging system, i.e., the CereTom™ CT machine. The CereTom™ CT machine is particularly well suited for use in stroke applications. More particularly, the CereTom™ CT machine is a small, mobile CT machine which can be pre-positioned in the emergency room and moved to the patient so that the patient can be scanned at their current location, on their emergency room bed or gurney, thus effectively eliminating “round-trip” delays between the emergency room and radiology department and thereby dramatically reducing the time needed to properly diagnose the patient.
The CereTom™ CT machine also has application in numerous other situations where patients may be located remote from the CT machine, e.g., other hospital departments such as Intensive Care Units (ICUs), nursing homes, rehabilitation centers, etc.
Since the CereTom™ CT machine is designed to be as small and mobile as possible, and since the CereTom™ CT machine is intended primarily for stroke applications and thus need only scan the head of the patient, it is configured so as to have a relatively small-diameter scan opening, i.e., a scan opening just large enough to receive the head of the patient. Furthermore, since the beds and gurneys typically found in emergency rooms are too large to fit within the scan opening of the CereTom™ CT machine, there is an urgent need for a narrow, X-ray transparent extender for selective attachment to the bed or gurney so as to support the patient's head during scanning, whereby the patient can be quickly and easily scanned while remaining on their bed or gurney.